Many firearms are equipped with a stock that has an adjustable length. Sometimes referred to as an “adjustable receiver extension,” this feature allows a user of a firearm to adjust a “length of pull” (i.e., a distance between a front face of a trigger and a user-confronting face of the stock) or “LOP” that better matches the physical configuration of the user's body. For example, a user with short arms (and thus a small LOP) can configure the length of the stock using an adjustable receiver extension to a shorter setting, thus customizing the LOP of the firearm to match the user's arm length. Upon adjusting the stock, the user need not stretch or strain to reach a trigger. Rather, an appropriately adjusted stock facilitates convenient use of a firearm by a user, regardless of the physical configuration of the user's body.